Artificial three dimensional oxide nanostructures for high performance correlated oxide nanoelectronics

We report a strategy for controlling nanoscopic electronic domains to produce gigantic Mott metal-insulator transition phenomena in strongly correlated oxides by fabricating oxide micro-nano-wires, nanowalls, nanoboxes. We investigated the dependence of spatial dimensionality on wire width for a disordered configurations of metallic domains in VO₂ microwires to nanowires on TiO₂(001) and Al₂O₃(0001) substrates with well-positioned alignment by a nanoimprint (NIL) technique. We observed a temperature-induced steep multistep metal-insulator transition in artificial VO₂ micro/nano-wires. With further development, we report a new bottom-up fabrication method for the formation of extremely small transition-metal oxide nanostructures employing a combination of NIL and pulsed laser deposition (PLD) techniques, called the three-dimensional nanotemplate-PLD method, to demonstrate functional oxide nanowall wires, nanoboxes, and hetero-nanowall oxide devices with widths of 20-120nm and excellent size controllability.